Apparatus for removing solids from gases



July 6,1m; 1,591,936

M. l. DORFAN APPARATUS FOR REMOVING SOLIDS FROM GASES Filed April 4, 1921 COLLECTE [7l/57' PaienieaJuly s, 1926.

mural) STATES 1,591,936 l PATENT OFFICE.

NORTON I. DOBFAN, OF NEW YORK, N. Y., ASSIGNOR TO ALLIS-GHALMEBS MANU- FACTURING COMPANY, OF MILWAUKEE, WISCONSIN, A CORPORATION OF DELA- APPARATUS FOR REMOVING SOLIDS FROM GASES.-

Appueation mea April 4,

. This invention in its material form, relates to a novel combination in which there are several units or compartments within which 'are suspended the collecting bags through and beyond which the air is drawn leaving part 'of the collected product deposited upon the fabric of which said bags are constructed. More particularly, this invention relatesto a proce of and apparatus for collecting dust whereby heated air or gases are introduced to supply the reverse iow necessary when the cleansing operation is in progress.

Themethod Aof operation for cleansing heretofore, has been to admit a current or draft from. the outside which passes through the particular compartment being cleaned simultaneously with the vshaking o the ba This plan admitted to the compartmente ements of lower temperature during the period of agitation when the said compartment was beclouded with dust in suspension affecting a change which would lower the dryin eciency of the medium so emplayed.

An object of this invention is to prevent atmospheric air" or chilling gases from entering the draft circuit of the dust collector through a compartment momentarily not as functioning asa collecting unit, by arranging means whereby the said compartment is connected to a pre-heated air source in such a wa that a countercurrent may be obtaine flowing through the bags of that 3s compartment, so as to prevent condensation of the inoisturein the gases or air.

IThis will be done by conning the entire dust collecting entirely within the several compartments by excluding contact with ie the outside atmosphere of lower temperature and by preventing the admission of air which would produce a greater humidity and would have a tendency to condense the moisture content of the air in a warm compartment, thereby depositing moisture upon the collector bags at a moment when these bags are being a 'tated to release the product they have co ected.

A still urtherobject is to avoid the disadvantages of exposing a warm compartment to the deleterious eect of a change in temperature between the inside and outside amospheric conditions at a point farthest when there is admitted an outside element 1921. Serial No. 458,505.

hment ,ofthe said collector. Mechanical ar.-

rangements were designed so as to reduce, to a minimum the time `of this exposure to outside conditions during the reversal.

The process of drying being one that ,requires heated air or other gases, it is obvious that the eiciency will be reduced that will chill the vcurrents coursing within. The eiliciency -is also reduced by the conditions met with at a point where these two elements -commingle in that a churning eect of hot and cold drafts creates a hesitancy during which the element of lower temperature prevents the process of dust deppsitii'ig from progressing asv-same would continue if no change toward lowering of the temperature had occurred. In the avoidance of the above practice this invention differs from the usages employed in the prior art by arranging other means whereby the products lsubjected to evaporating processes are never presented to conditions existing in outside atmospheric or other elements detrimentally differing from the conditions which prevail within. This invention is applicable to the case of a simple removal of dust from its gas ne carrier, as, in grinding and crushing mills :tor cement, lime or the like, or to the case where there is a preliminary separation of a solid from its liquid solution and its subsequent removal rom its vapor or gas carrier as in spray-dryers for millt or similar liquids.

-A clearer conception of the invention may be had'by referring to the drawing which forms part of this specification in which similar characters of reference apply to like parts throughout the several views.

Fig. 1 is a side elevation of a dust collector equipped with this improvement.

Fig. 2 is a section on line lli-U of Fig. ica

4 With the valve in reversal position.

ear

Fig. 3 is a section similar to Fig. 2 showing the valve rocked to normal position.

Fig. 4 is a section on line IV-IV of Fig. 2.

Fig. 5 is a diagrammatical section on line v v of Fig. 1.

The embodiment of this invention as illustrated, comprises a heating source, a spray-dryer, closed compartments, the latter arranged in battery form corresponding in number to the size of the collector desired, a fan, and reversing valves designed to interchangeably connect the compartments to the fan and either to the heating source or to the discharge from the dryer 4. Either dry products or products to be dried, along with the air or gas current actuated under forced draft or by suction, course through the several units that make up the installation illustrated. The several units` are labeled in Fig. 1 but are more particularly described as follows:-

A heater 2 for generating hot air or gases, is connected by the duct 3 to a dryer 4 into which is injected the products to be dried by means of the atomizer 5, conventionally shown. The hot air induces evaporation and absorption, in the dryer 4, ot the moisture content of the products injected and causes a partial deposit of these dried products to settle in the dryer 4 which has a hopper formation at its bottom for holding the residue so deposited. The lighter products are carried beyond the dryer 4 through the chiot G and introduced into thecompartments 7 of the collector by the common hopper 8 which also forms a depositary for the dust collected by the entire battery of compartments. The air currents are passed through bags 24 Within the compartments and -are draWnout at the upper ends of said compartments 7 into the exhaust chamber 9 which in turn discharges by virtue ot the motor driven fan into the discharge 10 which extends outside into the atmosphere. Thus is traced the path of the air through the dust collectors from atmospheric air or pure gas through a heater for the purpose of giving the drafts moisture evaporating and absorbing qualities, thence through the dryer Where commingling with the products to be dried is established, thence through the compartments of the collector where the remaining particles are filtered out, then through the exhaust chamber 9 and the fan as before mentioned.

There are periods of short duration when a reverse flow is required and to avoid supplying atmospheric air, heretofore customarily supplied there is provided the reverse duct 12 which receives its supply of heated air from the heater 2 or by connection to the fan exhaust, and in turn supplies same through the pipes 13 to the valve chambers l14 positioned on top of the compartments 7. These valves 15 in chambers 14 serve to connect, interchangeably, the said compartments either with the exhaust chamber 9, or with the duct 12 through pipes 13, at

periods of time determined and controlled b v mechanical means, omitted for clearness sake, in Fig. 1 but disclosed in Figs. 2 and 3. These periods ot time are such that there is at all times, at least, one compartment in process ot being cleaned, for the purpose ot' keeping in motion, the gas in the reverse duct. 12 so that the same will not have time to cool by radiation.

The valve chambers li, Fig. 2, illustrating the period tor shaking the bags, artl supplied with butterfly valve gates 15 artuated by any suitable means as illustrati-d and operable through the shafts It. 17. a construction common to valve chamber;-- ot' this class and uell known in the art, (see Newhouse ll. S. Pat. 1,168,513). Formed integral with said gates 15 are the passages or chambers 1S, the wings 19 and the flanges 20'.' The wings 19 open or shut otl' the reverse draft inlets 21 ot' the pipes 1S entering the sides of the valve chamber 14, said draft coursing as indicated by the arrows to join, in the hopper 8, the direct flow that is passing upward through the other compartments which are now functioning normally. The'flange 20, of the gate 15 places thepassages 18 in or out of registry with the opening 22, the latter formed in thc seat 23. The flange 2O is provided with a recess 25 to prevent contiict with a central vertical bag supporting rod, when the valve is rocked to establish communication between the compartment 7 and exhaust chamber 9 as disclosed in Fig. 3 illustrating an opposite condition to that shown in Fig.

The valve 15, When so rocked, alloivs the flow of air to course as per arrows, the wings 19 having closed the reverse drat't inlets 21 and the valve 15 having established direct communication between the compartments 7, with their complement ot bags 24, and the exhaust chamber $1, through the opening 26. The conditions described are determined by the setting ot' the valve mechanism.

A The action described completes one cycle of the air current functions and sets forth operations that are always confined to the interior of the apparatus excluding all communication with the outside air and its deleterious effects of temperature and humidity` and by supplying a heated reverse draft. from the same heating source as the direct. draft by a simple construction that is eminently efficient and structurally economical, the cleaning of the bags is successfully accomplished.

It should be understood that it is not. desired to limit the present invention tothe exact steps of the process described or to the exact details of construction of the apparatus shown and described, for obvious modifications will occur to a person skilled in the art.

It is claimed and desired to secure by Letters Patent:

l. In combination, a plurality of lter bags, a source of preheated gas, a desiccating device, a fan for drawing preheated gas from said source through said desiccatng device and through said bags, land a valve for successively effecting reversal of flow of preheated gas to cause it to How directly from said source through said bags to the suction of said fan.

2. In combination, a plurality of groups of filter bags, a source of preheated gas, a

desiccating device, a fan for normally drawing preheated gas from said source through said desiccating device and through several of said groups, and a valve for suc- Jcessively effecting reversal of flow of preheated gas to cause it to flow directly from said source through one of said groups and through adjacent groups to the suction of said fan.

'3. In combination, a permeable filtering medium, a source of preheated gas, a desiccating device, a fan for drawing preheated gas from said source through said desiccating device and through said medium, and means for utilizing said fan to draw preheated gas from said source through said medium 1n a reverse direction.

In testimony whereof, the signature of the inventor is aliixed hereto.

MORTON I. DORFAN. 

